Thermal epoxy and positioning of electrochemical cells

Abstract

The present disclosure includes a battery module having a housing with a first end (having a cell receptacle region) and a second end opposite to the first end. The battery module includes a stack of electrochemical cells inserted through the cell receptacle region of the housing, disposed between the first end and the second end of the housing, and having terminal ends of all the electrochemical cells of the stack aligned in a planar area. The battery module includes a bus bar carrier disposed over the stack of electrochemical cells and within the cell receptacle region of the housing. The bus bar carrier includes bus bars disposed thereon that interface with the terminal ends. The battery module includes a layer of thermal epoxy disposed between the second end of the housing and a bottom side of the stack of electrochemical cells.

The invention claimed is: 
     
       1. A battery module, comprising:
 a housing having a first end and a second end opposite to the first end, wherein the first end comprises a cell receptacle opening and the second end comprises a wall with an inner surface; 
 a plurality of electrochemical cells, one or more of which of varying height, each one of the plurality of electrochemical cells comprises, respectively:
 a terminal end; 
 a base end; 
 a first terminal having a first surface; and 
 a second terminal having a second surface; 
 
 a plurality of adhesive layers; 
 a stack formed by the plurality of electrochemical cells and the plurality of adhesive layers, wherein each adhesive layer of the plurality of adhesive layers is disposed between, and in contact with, adjacent electrochemical cells of the plurality of electrochemical cells such that the adjacent electrochemical cells are adhesively joined and such that the terminal ends of the plurality of electrochemical cells are aligned in a first planar area and the base ends of one or more of the plurality of electrochemical cells are disposed in different planes, wherein the stack is configured to be received by the housing through the cell receptacle opening, and wherein the first surfaces of the first terminals and the second surfaces of the second terminals are aligned in a second planar area; 
 a layer of thermal epoxy disposed between the inner surface of the wall of the second end of the housing and the base ends of the plurality of electrochemical cells opposite to the terminal ends and enabling the alignment of the terminal ends of the plurality of electrochemical cells of varying height when seated in the housing; and 
 a bus bar carrier disposed in the cell receptacle opening, the bus bar carrier retaining bus bars disposed thereon, wherein the terminals are configured to extend through openings in the bus bar carrier to access the bus bars disposed on the bus bar carrier, wherein the terminals do not extend above a plane of a surface of the bus bar carrier on which the bus bar is positioned, the bus bars being electrically coupled to and abutting the first surfaces of the first terminals and the second surfaces of the second terminals extending from the aligned terminal ends of the plurality of electrochemical cells. 
 
     
     
       2. The battery module of  claim 1 , wherein the wall of the second end of the housing is at least partially formed by the heat sink, wherein a first face of the layer of thermal epoxy is configured to physically contact the base ends of the plurality of electrochemical cells, and wherein a second face of the layer of thermal epoxy opposite to the first face physically contacts the heat sink. 
     
     
       3. The battery module of  claim 1 , wherein the plurality of electrochemical cells comprises a plurality of prismatic, lithium-ion (Li-ion) electrochemical cells. 
     
     
       4. The battery module of  claim 1 , wherein the layer of thermal epoxy comprises a volume per electrochemical cell of 0.83-2.5 cubic centimeters. 
     
     
       5. The battery module of  claim 1 , comprising an additional stack formed by an additional plurality of electrochemical cells and an additional plurality of adhesive layers, wherein the additional stack is configured to be received by the housing through the cell receptacle opening, and wherein the plurality of electrochemical cells are not adhesively joined to the additional plurality of electrochemical cells via the plurality of adhesive layers or by the additional plurality of adhesive layers. 
     
     
       6. The battery module of  claim 5 , wherein the plurality of electrochemical cells comprises three electrochemical cells and the additional plurality of electrochemical cells comprises three additional electrochemical cells. 
     
     
       7. The battery module of  claim 1 , wherein the bus bar carrier is arranged such that all the bus bars are disposed an equal distance from the stack. 
     
     
       8. The battery module of  claim 1 , wherein the layer of thermal epoxy comprises a volume in the range of 5 to 15 cubic centimeters.